After a recent power loss my Gentoo system stopped booting and displayed kernel panic instead. It turns out that my root partition can't be mounted. I've used SystemRescueCD to scan partition for errors while it was unmounted, but I got a "bad superblock" error. I've already tried to use backup superblocks, but it didn't help.

The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>

The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>

Check your dmesg (1) to see if Linux is having problems reading your SSD... It may have croaked :(_________________Intel Core i7 2700K@ 4.1GHz/HD3000 graphics/8GB DDR3/180GB SSDWhat am I supposed to be advocating?

I think the e2fsck is fine using the block numbers straight from mke2fs -n, but mounting requires the offset correction. Also what happens if you skew the block by one... and are you sure you made the filesystem initially with 4K blocks?

Did you check your dmesg log after trying to read the disk? Did the kernel report issues? It might have been a few bad sectors here and there, just want to make absolutely sure because reading a different partition doesn't mean the sectors in the partition you're having trouble with are still good._________________Intel Core i7 2700K@ 4.1GHz/HD3000 graphics/8GB DDR3/180GB SSDWhat am I supposed to be advocating?